Respiration Flashcards
What does carbon monoxide do to the blood?
Displaces oxygen
Why might a pilot suffer carbon monoxide poisoning?
Leaky exhaust
What are the symptoms of carbon monoxide poisoning?
Headache Fatigue Uncomfortable breathing Impaired vision Confusion
Why are smokers more. Susceptible to hypoxia?
Smoking adds carbon monoxide to the bloodstream reducing oxygen capacity
What gives rise to hypoxia and how is it treated? At what altitudes is it to be expected?
Reduced partial pressure of O2 in lungs (above 10000ft). Treat by increasing the partial pressure (breathe pure O2). Need to breathe pure O2 above 40000ft unless cabin pressurised
Why does the usual bodily response to low blood oxygen fail at altitude?
The brain measures CO2 levels not O2. Normally, low O2 is accompanied by high CO2 (physical exertion conditions). The brain then triggers hyperventilating (puffing).
Low O2 at altitude is undetected as there is no CO2 rise
What are the effects of hypoxia?
Similar to mild alcohol with reduced night vision.
In the later state: euphoria, impaired judgement and an overperformance illusion
Advanced state: cyanosis (blue lips, fingernails)
How long does it take to recover from hypoxia when given oxygen?
A few seconds after a few breaths - you won’t remember the incident
What are the times of useful consciousness / effective performance times for 20000,25000 and 30000 ft?
10,3,1 min (moderate activity)
20,5,3 min (sit quietly)
When must supplemental oxygen be carried?
10000ft
What factors exacerbate hypoxia?
Smoking (a smoker is 'at 8000ft' at sea level) Cold/flu Alcohol Emphysema/asthma (etc) Anaemia Heart disease
